chart
viewof chart = {
const svg = d3.create("svg")
.attr("viewBox", [0, 0, width, height]);
const brush = d3.brushX()
.extent([[margin.left, margin.top], [width - margin.right, height - margin.bottom]])
.on("start brush end", brushed);
const circle = svg.append("g")
.attr("fill-opacity", 0.2)
.selectAll("circle")
.data(data)
.join("circle")
.attr("transform", d => `translate(${x(d)},${ry()})`)
.attr("r", 3.5);
svg.append("g")
.call(xAxis);
svg.append("g")
.call(brush)
.call(brush.move, [3, 5].map(x))
.call(g => g.select(".overlay")
.datum({type: "selection"})
.on("mousedown touchstart", beforebrushstarted));
function beforebrushstarted(event) {
const dx = x(1) - x(0); // Use a fixed width when recentering.
const [[cx]] = d3.pointers(event);
const [x0, x1] = [cx - dx / 2, cx + dx / 2];
const [X0, X1] = x.range();
d3.select(this.parentNode)
.call(brush.move, x1 > X1 ? [X1 - dx, X1]
: x0 < X0 ? [X0, X0 + dx]
: [x0, x1]);
}
function brushed(event) {
const selection = event.selection;
if (selection === null) {
circle.attr("stroke", null);
} else {
const [x0, x1] = selection.map(x.invert);
circle.attr("stroke", d => x0 <= d && d <= x1 ? "red" : null);
svg.node().value = [x0, x1];
svg.node().dispatchEvent(new CustomEvent("input"));
}
}
return svg.node();
}
data = Float64Array.from({length: 800}, rx)
xAxis = g => g
.attr("transform", `translate(0,${height - margin.bottom})`)
.call(d3.axisBottom(x))
x = d3.scaleLinear([0, 10], [margin.left, width - margin.right])
rx = d3.randomUniform(...x.domain())
ry = d3.randomNormal(height / 2, height / 12)
margin = ({top: 10, right: 20, bottom: 20, left: 20})
height = 120
d3 = require("d3@6")
Purpose-built for displays of data
Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
